PHP/DNS/gethostbyaddr
Determining the Hostname of a Remote IP
<source lang="html4strict">
<?php
$hostname = gethostbyaddr($_SERVER["REMOTE_ADDR"]);
if($hostname === $_SERVER["REMOTE_ADDR"]) {
echo "The host name could not be resolved.
\n";
} else {
echo "The host name is: $hostname
\n";
}
?>
</source>
Using gethostbyaddr() to Get a Hostname
<source lang="html4strict">
<html> <head> <title>Using gethostbyaddr() to get a host name</title> </head> <body>
<?php if ( ! empty( $_SERVER["REMOTE_HOST"] ) ) {
print "Hello visitor at ".$_SERVER["REMOTE_HOST"];
} else if ( ! empty( $_SERVER["REMOTE_ADDR"] ) ) {
print "Hello visitor at "; print gethostbyaddr( $_SERVER["REMOTE_ADDR"] );
} else {
print "Hello you, wherever you are";
} ?>
</body> </html>
</source>
